JPS5894786A - Panel heater - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sheet heating element used in electric carpets and other heating devices.

BACKGROUND ART Conventionally, a sheet heating element has been used, which has a heat generating printed wiring circuit, which serves as a heat generating wire section and a lead wire section, on the surface of an insulator. This planar heating element is usually made as follows. A metal foil is formed on the surface of an insulating film or other insulating sheet made of nylon, polyethylene, etc. by adhesion of a metal foil or vapor deposition of a metal. Next, resist ink (corrosion-resistant paint) is applied to the predetermined wiring circuit forming portions of the 1 Kinkohaku foil using a printing method, which will become the heating wire portion and the lead wire portion.
The blank areas of the metal foil that will not be printed are chemically treated (etched) and then melted away using electrolytic treatment. In this way, a heat generating printed wiring circuit made of gold lI foil can be obtained. Then, if necessary, an insulating sheet is pasted on the printed wiring circuit with an adhesive to form a planar heating element.

An example of a planar heating element obtained in this manner is shown in Fig. I11. As shown in the figure, two pieces of insulation film 1m, lb
A heat generating printed wiring circuit 2 made of metal foil is sandwiched between them. In the figure, 3 indicates the Lensto ink and 4 indicates the adhesive layer.

Printing machines are generally used to print wiring circuits.

However, at present, due to limitations on the width of the printing press and the diameter of the printing cylinder, it is not possible to print a wiring circuit with a width and length of 900 mm or more by printing with one rotation of the cylinder. Therefore, the following steps are taken to industrially obtain a large sheet heating element. A wiring circuit unit pattern is repeatedly printed on a long metal foil-clad insulating film or the like. Next, chemical treatment etc. are performed as described above, and the heat generating printed wiring circuit 2a is made up of continuous unit turns Al, A2, etc. separated by two-dot chain lines as shown in FIG. 2(a). An insulating film 1a is obtained. Putter/Al
, Ag... are fmJ-patterns, which continuously form the wiring circuit 2a. In the figure, arrow Y indicates the printing direction. The meandering portion of the wiring circuit 2a is the heating wire portion 5a, and detailed illustration of the intermediate portion is omitted here. Each unit pattern A,,A2・
The heating wire portions 5a of 00 are connected by a lead wire portion 6a.

For example, two unit turn A1. To obtain a planar heating element with Az, the insulating film 1a is cut along the two-dot chain lines 7a and 7b, and then short-circuited parts and unnecessary parts of the wiring circuit 2a are cut. That is, each unit pattern AI, A is provided with terminal portions 9m, 9b for connecting the cord, but the terminal portion 9 of unit no<turn At
If you want to connect the cord to a, 9b, please enlarge the dot-dashed line circle CI, Cz part in Figure 2 (value in Figure 2).
Then, in (C), the parts indicated by loa and 10b are punched.

To obtain a wide planar heating element, proceed as follows. For example, as shown in FIGS. 3 and 4, two unit numbers (turns A, , A) as described above.

Two insulating films la provided with the above are arranged in parallel to form a planar heating element. In Figure 4, one of the two cards is placed face down. In these figures, the terminal part 9 of the unit pattern
Only a and 9b are shown, and the remaining wiring circuits are omitted. In the case of the planar heating element shown in FIG. 1#I3, when a cord is connected to the terminal portions 9m and 9b of the two Al patterns, since both are separated, two exits for the cord are required, which is inconvenient in use. Also, in the sheet heating element shown in Fig. 4, the two Al pattern terminals 9a and 9b are adjacent to each other, so the cord only needs to exit from one place, but the cord comes out from the center of the sheet heating element. Therefore, this is also inconvenient to use.

The following are planar heating elements that eliminate this inconvenience. A heat generating printed wiring circuit 2b consisting of four unit patterns B1 to B4 as shown in FIG.
An insulating film 11 is prepared. In the figure, arrow Y indicates the printing direction. In this case, short-circuited parts and unnecessary parts of the wiring circuit have already been cut off. Unit pattern B2
84 and unit pattern B2 are placed next to unit pattern B1 as shown in FIG.
Fold the insulating film la so that B3 is placed next to it to make a planar heating element. And unit pattern B! If the cord is connected to the terminal portions 9a and 9b, the cord only needs to exit from one place, and moreover, it exits from the corner of the planar heating element.

Also in FIGS. 5 and 6, the heating wire portion 5b of the wiring circuit 2b is shown with the intermediate portion omitted. In this way, a planar heating element of a desired size can be obtained.

However, the nine conventional planar heating elements described above have the following drawbacks. This is a drawback in that the watt density (W/m") is low near the boundary between the unit patterns of the planar heating element, that is, the lead wire portion, and the temperature rise is suppressed compared to other parts, resulting in a lower temperature. The reason for this is as follows.In order to make a large planar heating element, it is necessary to repeatedly print the unit pattern of the heating printed wiring circuit as many times as necessary, as described above. A lead wire section is always required to connect.Also, as shown in Fig. 6, the size of the lead wire section may be reduced during transportation by making a cut between the two unit patterns and bending it. The parts were arranged perpendicular to the printing direction, i.e., as shown in Figures 2 and 5.
Like the conventional unit pattern shown in the figure.

By the way, in general, when printing lines extending perpendicular to the printing direction, it is necessary to make the line spacing wider than when printing lines along the printing direction. This is because if there is a problem with the doctoring of the ink, that is, if there is a problem with scraping off the excess ink, there is a risk that the lines will stick together and be printed, and if a wiring circuit is created by chemical treatment, a short circuit will occur at this part. This is because Normally, when perpendicular to the printing direction, a line spacing of at least 5 to 7 rrtn is required. On the other hand, for those along the printing direction, the line spacing may be about 1 mm. On the other hand, most of the heating wire parts that run along the printing direction have a high linear density, that is, the watt density can be increased to increase the temperature, but the lead wire part, like the heating wire part, has a high linear density. It is not possible to increase the density, and the temperature rises slowly in this area.

Furthermore, if the planar heating element is equipped with two printed wiring circuits of different wattage so that the wattage can be switched, for example, the number of lead wires will be doubled, and the temperature will rise even more slowly in this part.

The present invention has been made in view of the above circumstances, and provides a planar heating element that has a uniform watt density and therefore a uniform temperature. This will be explained below.

The planar heating element according to the present invention K is a planar heating element that is provided with a heat generating printed wiring circuit serving as a heating wire portion and a lead wire portion on an insulating sheet, and the printed wiring circuit is provided on both the front and back sides of the insulating sheet. When the watt densities of the heat generating printed wiring circuits on the front and back surfaces of the planar heating element are combined and compared between the two surfaces, the imbalance between the various locations within the surface of the sheet heating element is reduced. It is characterized by its wiring design. The present invention will be described below based on embodiments shown in the drawings.

FIG. 7 shows an example of a planar heating element according to the present invention. As shown in the figure, this planar heating element has an insulating film 1c
The first printed wiring circuit 2C for heat generation and the second
The heat generating printed circuit 2d is provided with an insulating film 1 on the surface of the first wiring circuit 2c and the insulating film lc.
d is attached, and an insulating film le is attached to the back surface of the second wiring circuit 2d and the insulating film lc. In the figure, 4 is an adhesive layer. The manufacturing method of this planar heating element differs from the conventional method only in that two metal foils are provided on the front and back sides of the insulating film lc, and the rest is the same as the conventional method. A method of designing the wiring of the first wiring circuit 2C and the second wiring circuit 2d will be explained using FIG. 8. As described below, when comparing the watt densities of the heat generating printed wiring circuits on the front and back surfaces at various locations within the surface of the sheet heating element, the watt densities on both surfaces are combined. Imbalances are beginning to decrease. That is, in the part where the line density of the heat generating printed wiring circuit of aIl is low, for example, the back side of the lead wire s11, the line density of the second heat generating printed wiring circuit is increased, and the line density of the heat generating printed wiring circuit of tml is high. The line density of the second heat generating printed wiring circuit is made low in some parts, for example, on the back side of the heat generating wire section 12. In this way, the linear density, ie, watt density, of the entire planar heating element is uniform, and the temperature of the entire heating element is uniformly increased.

FIG. 9 shows the first heat generating printed wiring circuit 2C and the second
An example of the wiring design of the heat generating printed wiring circuit 2d is shown, each of which has six unit patterns. In the figure, A
indicates one unit pattern range. As shown in the figure, a portion of the first wiring circuit 2C with a low line density has a high line density of the second wiring circuit 2d, and a portion of the first wiring circuit 2C with a high line density has a high line density of the second wiring circuit 2d. The linear density of is low. In the figure, 13 is a printed wiring circuit for controlling temperature, etc., and is located on the same side as the second wiring circuit 2d.

This control wiring circuit 13 is not necessarily required. After separating the short-circuited parts and unnecessary parts of the heating wiring circuits 2c and 2d, make a cut in the solid line 14 and fold it in the same manner as shown in FIG. 6 to obtain a wide planar heating element. can be obtained. Friend, it is convenient if the cord is connected to the next terminal part 15 surrounded by the dashed dotted line in the figure, since the cord can come out from the corner of the planar heating element.

In the above embodiment of the planar heating element, the first wiring circuit 2C and the second wiring circuit 2d are provided on the insulating film lc as shown in FIG. However, other insulating sheets may also be used. i9. The insulating films ld and le may also be other insulating sheets, and may not necessarily be attached with an adhesive, but may be welded or the like. However, the insulating films ld and le are not necessarily required. This planar heating element is sometimes supplemented with metal foil to prevent electric shock.

The sheet heating element according to the present invention is configured as described above, and a printed wiring circuit (heating wiring circuit) is provided on both the front and back surfaces of the insulating sheet, and the printed wiring circuit (heating wiring circuit) is provided on both the front and back surfaces of the insulating sheet. Layout of the printed wiring circuit on each side of the front and back) If
Since the wiring design is such that when f is compared with the combined watt density of both sides, the imbalance between various parts in the plane is reduced, the temperature of the whole increases uniformly.

[Brief explanation of the drawing]

Fig. 1 is a partial vertical cross-sectional view of a conventional planar heating element, Fig. 2 is an explanatory diagram of an insulating film equipped with a heat generating printed wiring circuit,
Figures 3 and 4 are schematic plan views showing examples of a sheet heating element with four unit patterns, respectively, and Figures 5 and 6 are diagrams showing examples of a sheet heating element with a four-unit pattern with cord outlets at the corners. FIG. 7 is a partial vertical sectional view showing an example of the sheet heating element according to the present invention, and FIG. An explanatory diagram of the wiring design of the heat generating printed wiring circuit, FIG. 9 is an example of the wiring design of the first heat generating printed wiring circuit and the second heat generating printed wiring circuit, and the assembly of a sheet heating element with six unit patterns. FIG. lc, ld, 1e”・Insulating film 2cm First printed wiring circuit for heat generation 2d...Printed wiring circuit for heat generation of li2 4...Adhesive layer 11...Lead of first printed wiring circuit for heat generation Wire portion 12... Heat generating wire portion of the first heat generating printed wiring circuit Fig. 1 (a) (t)) (C) Fig. 2 Fig. 3 Fig. 4 Fig. 6 Fig. 5 Fig. 7

Claims (1)

[Claims] (1) A round heating element comprising a heat generating printed wiring circuit serving as a heating wire part and a lead wire part on an insulating sheet, the printed wiring circuit being visible on both the front and back sides of the insulating sheet, and having a round shape. The wiring is designed so that the watt density of the heat generating printed wiring circuit on each side of the front and back surfaces of the heating element at various points on the surface of the heating element is reduced when comparing the watt densities of both sides together. A sheet heating element characterized by: (The sparse part of the heat generating printed wiring circuit on the insulating sheet front WiK is the dense part of the heat generating printed wiring circuit on the back side, and the dense part of the heat generating printed wiring circuit on the front surface is KINK) ′
Claims ts in which the parts are each arranged in 1111
The planar heating element according to item 1.